Cutting plywood with a circular saw...

The plywood provides shear strength, but the splintering should not affect strength. You could avoid the splintering with a new saw blade. There are different types for different woods and different cuts. Someone at your local hardware or lumber store should be able to help you choose the right one. Good luck!

It depends on how bad the splintering is. To minimize spintering make the blade depth just a hair over the thickness of the plywood. Another method to help minimize splintering is to use masking/painting tape. You tape the line you are going to cut then draw your cut line onto the tape. Good Luck

The ideas already stated are good ones.

Also, a finish carpentry grade blade, nice and sharp will produce finer cuts with even less splintering.
Draw an exact line on both sides of the board, then using a straight edge for a guide, use a razor knife to score the outer layer of ply (on the backside) down your line.

Make sure the scoreing cut stays just inside the blade cut by scoring about 1/16" inside the line.

Now the outer layer has a precise edge precut, and with a good blade, you will have no splintering.

All good suggestions that will help. I'm assuming that you're using a universal circular saw blade with larger teeth. If you switch to a high quality blade with finer teeth then it will cut down on splintering as well. Look for one that has either carbide or titanium tipped teeth. It may be more expensive up front but will last much longer therefor saving you money in the long run.

If you use the proper blade, you shouldn't have splintering. Get a blade made for cutting plywood:http://www.google.com/products/cata...a=X&ei=pL--TprNBITy0gGas7HtBA&ved=0CGgQ8wIwBQ

One thing to remember is that a circular saw cuts the bottom of the wood clean and splinters on the top, due to the direction the blade spins. So mark all your cuts on the back side of what you want to see. I also like the idea of scoring the line with a razor knife to minimize splintering.

Hello; Add a square or two to the tool list (An L shaped tool with a true 90 degree corner) If you decide to get just one get a large one. A four foot straight edge is also very handy.

You can also use a 2X4 or some similar straight edge clamped onto the plywood for a straight cut. Run the table of the circular saw along the straight edge. Just don't forget to take into account the distance between the table edge and the inside edge of your saw. On mine, I set my straight edge 1.5" behind my cut line, so my blade cuts right on the outside of my line.